Paint equipment from time to time will need to be cleaned. The equipment will need cleaned when there is a build up coating material on the paint equipment or when switching between coating materials.
Purge solutions can be used to clean paint equipment. When using purge solutions, it is desired to minimize the volatile organic content (VOC) of the purge solution to minimize the amount of organic emissions.
One type of paint equipment is a high-speed rotary atomizer. Paint is supplied through a bell cup. As the paint supply is triggered on and off, paint can dry on the bell. A purge cycle is used to clean the bell by supplying alternating amounts of purge solution and air through the atomizer. Materials that are hard to clean require purge solutions with higher concentration of solvents or large volumes of purge solution to clean the material. This can result in increased VOC emissions.